PolyJet 3D printing’s benefits for prototyping

By using PolyJet features like full color, graphic textures and multiple materials, designers, engineers and product development teams can create prototypes that accurately simulate end-product look and feel.

Matt Stenoien, Product Manager, Stratasys Direct Manufacturing

With pressure to get to market quickly, product designers and development teams must make fast and accurate decisions during the early stages of design and testing. Rapid prototyping is a key component for design verification, and 3D printing offers the fastest method for prototyping. While the 3D printing industry offers several fast technologies, PolyJet technology is one of the more impactful, popular methods for prototyping.

The PolyJet process begins with your design in the form of 3D CAD data. The system’s printhead both jets and cures photopolymer material nearly simultaneously, cross-section by cross-section, with ultraviolet (UV) light. The machine adds support structures using specially formulated material to support free-floating features. After each cross-section, the build platform lowers, and the process repeats until the full part is formed. With the 3D printer’s ability to produce parts rapidly and in precise detail, PolyJet is an excellent technology for quick delivery of accurate and cosmetic prototypes and concept models. The technology produces parts with fine layers as thin as 27 microns (0.00106 in.), intricate details, and in full color.

A gearshift prototype 3D printed on a PolyJet system in multiple materials and colors. Courtesy of Stratasys Direct Manufacturing.

Below is a breakdown of PolyJet as a solution rapid prototyping, and how it can benefit designers and engineers during product development.

Speed
3D printing has historically been used as a rapid prototyping method because of the simplicity of the process — a 3D design is uploaded into a computer and the printer uses that data to build the design layer by layer. The design is in an engineer’s hands usually that same day. This contrasts sharply with the long-lead times and set up costs associated with other prototyping methods such as molding and machining operations.

The Stratasys J750 PolyJet system is one of the fastest 3D printers in market. Courtesy of Stratasys Direct Manufacturing

Build speed is largely determined by part size and resolution. Even so, PolyJet continues to be one of the fastest 3D printing technologies in the market. The technology can build multiple parts in a matter of hours, enabling product development teams to receive imperative feedback, revise, and reiterate within days. PolyJet is most efficient for small, detailed parts. Designs within a 5 to 6-in. cubed area leverage the speed, surface finish, detail and low price point of PolyJet.

Geometric freedom
3D printing gives you freedom to design. Traditional design for manufacturability rules don’t apply because the technology can build complex geometries with cavities, undercuts, overhangs and more. What may have been an impossible design to machine is now feasible. You have the freedom to let function and performance be the main drivers of design, rather than cost, time or the limitations of traditional manufacturing methods.

PolyJet can deliver a minimum feature size of 0.012 in. and layer thicknesses as thin as 27 microns (thinner than human hair). Because the 3D printing process doesn’t use heat to fuse layers together, warping and shrinking are not a concern. A designer can take advantage of the technology’s build features to create finely detailed prototypes unburdened by the constraints of traditional manufacturing.

Full color
One of the biggest challenges designers face when prototyping is meeting the seemingly contrasting needs for an accurate, aesthetic model that is also delivered quickly. In addition to being fast, PolyJet technology produces cosmetic parts in full color.

PolyJet offers a full range of CMYKW color options – 360,000. Graphics and pictures can be incorporated via images that further the visual complexity that can be achieved, like wood grain or bricked surfaces. Designers can add transparencies to their models to display interiors, simulate glass or other see-through elements. Companies can reduce time to market by enabling graphic designers to integrate product images in marketing materials and ensure that packaging and displays work seamlessly with end products well before the design goes into actual production.
The models can be nearly indistinguishable from the end product, mimicking the final part’s look and feel for concept reviews and promotional uses. The PolyJet parts are built with the desired visual aesthetic quickly without the need for additional finishing.

Color can be incorporated with two file formats, depending on the desired color and characteristics of the part. With STL files, color and transparency are determined by RGB color code assigned to each unique shell. In VRML format, color can be applied to each face or individual triangles of the geometry or with a texture (graphic) file. Texture mapping, also known as UV mapping, is the process of adding an image or graphics to 3D geometry. Color information is stored in a 2D image file (.png, .jpg, .tiff), which is related to the coordinates of the mesh.

Through the high-resolution of PolyJet technology, prototypes and concept models can accurately mimic the final product as soon as it comes off the 3D printer without post-processing.

Multiple materials
Material versatility is another significant benefit of PolyJet for rapid prototyping. PolyJet materials like Digital ABS Plus simulate engineering-grade plastics that may be used in the final product. The Agilus30 family of PolyJet materials, for example, simulate thermoplastic elastomers with flexible, rubber-like qualities. Glass-like clear materials further enhance the range of visual capabilities available with PolyJet. Multiple material types can be used in conjunction to support a range of visual, tactile and functional simulation for advanced prototypes and concept models. Incorporating rubber surrounds, overmolds, buttons, knobs, grips, gaskets and boot and hose assemblies can increase the realism of a prototype used for stakeholder feedback or for marketing materials.

PolyJet materials offer the versatility to allow team members to see, touch, feel, test, analyze and use prototypes as they would the final product. These prototypes are tested or used in trials to gauge their success and enable rapid iterations. By using the benefits of PolyJet like full color, graphic textures and multiple materials, designers, engineers and product development teams can create unparalleled prototypes that accurately simulate end-product look and feel.

Ultimately, PolyJet prototypes give designers a thorough understanding of products earlier in the development process, minimizing the risk that problems will go unnoticed. With fine feature details and little need for finishing, designers and engineers can be more confident in their work as they move forward in the product development life cycle.Stratasys Direct Manufacturingwww.stratasysdirect.com